If you really want to learn how a quantum chemistry algorithm works the only way is really to write it (or a simplified version of it) yourself. Daniel Crawford has made this wonderful page of projects that covers everything from harmonic vibrational analysis to coupled cluster (no DFT unfortunately).
It's geared towards C++ so this might also be a good way to learn that. However, if you are familiar with python you should be able to complete the exercises in that language.
CCH is an overlay journal that identifies the most important papers in computational and theoretical chemistry published in the last 1-2 years. CCH is not affiliated with any publisher: it is a free resource run by scientists for scientists. You can read more about it here.
Table of content for this issue features contributions from CCH editors Steven Bachrach and Jan Jensen: